tests/testthat/test-rq.R

In strengejacke/ggeffects: Create Tidy Data Frames of Marginal Effects for 'ggplot' from Model Outputs

skip_on_os(c("mac", "solaris"))
skip_if_not_installed("quantreg")
skip_if_not_installed("effects")

test_that("ggpredict, rq", {
  data(stackloss)
  m1 <- quantreg::rq(stack.loss ~ Air.Flow + Water.Temp, data = stackloss, tau = 0.25)
  expect_warning({
    pr <- ggpredict(m1, "Air.Flow")
  })
  expect_equal(pr$predicted[1], 10.09524, tolerance = 1e-4)

  # ggeffect
  expect_null(ggeffect(m1, "Air.Flow", verbose = FALSE))

  # emmeans
  skip_if_not_installed("emmeans", minimum_version = "1.9.0")
  out <- ggemmeans(m1, "Air.Flow", verbose = FALSE)
  expect_equal(out$predicted[1], 10.09524, tolerance = 1e-4)
  expect_identical(dim(out), c(7L, 6L))
})


test_that("ggpredict, rqs, multiple taus", {
  data(stackloss)
  m2 <- quantreg::rq(
    stack.loss ~ Air.Flow + Water.Temp,
    data = stackloss,
    tau = c(0.25, 0.5, 0.75)
  )
  out3 <- ggpredict(m2, "Air.Flow [50,55,60]")
  expect_equal(
    out3$conf.low,
    c(
      8.10594, 7.29479, 3.98695, 11.95882, 12.14723, 10.9099, 13.15987,
      15.5423, 16.92013
    ),
    tolerance = 1e-4
  )
})


test_that("ggemmeans, rqs, multiple taus", {
  skip_if_not_installed("emmeans", minimum_version = "1.9.0")
  data(stackloss)
  m2 <- quantreg::rq(
    stack.loss ~ Air.Flow + Water.Temp,
    data = stackloss,
    tau = c(0.25, 0.5, 0.75)
  )
  out <- ggemmeans(m2, "Air.Flow [50,55,60]")
  out2 <- as.data.frame(suppressWarnings(emmeans::emmeans(
    m2,
    specs = c("Air.Flow", "tau"),
    at = list(Air.Flow = c(50, 55, 60))
  )))
  expect_equal(out$predicted, out2$emmean[order(out2$Air.Flow)], tolerance = 1e-4)
  # validate against ggpredict
  out3 <- ggpredict(m2, "Air.Flow [50,55,60]")
  expect_equal(out$predicted, out3$predicted, tolerance = 1e-4)
})